responseHeaders['set-cookie'] better stores in an array?

[OKFred]

undici/lib/fetch/index.js

Line 1952 in 6a87bfb

headers.append(key, val)

When it comes to response headers: 'set-cookie', the value stores as a string as well.
The problem is that there may be multiple 'set-cookie' headers in various of formats sent from the server.
Hard to split when joined in a string. (Or, do you have any better ideas defining the splitter? Coz I am a newbie)

It would be easier to handle as an array.
Reasons/References are as follows:

• In older ways, it stores as an array. Quotes: set-cookie is always an array. Duplicates are added to the array.
  https://nodejs.org/api/http.html#messageheaders

• And node-fetch package implemented this way as well, which you may have referred.
  https://github.com/node-fetch/node-fetch/blob/main/src/index.js#L65

Thx & B/R
Fred

[ronag]

This is how the fetch spec defines the behavior and is not something I believe we can change.

[mcollina]

See wintercg/fetch#7.
As soon as a spec-compatible API is available, we'll implement it.

[OKFred]

@ronag Are you referring to the Fetch Standard? https://fetch.spec.whatwg.org/#headers-class
The following quotes could be quite informative:
Unlike a header list, a Headers object cannot represent more than one Set-Cookie header. In a way this is problematic as unlike all other headers Set-Cookie headers cannot be combined, but since Set-Cookie headers are not exposed to client-side JavaScript this is deemed an acceptable compromise. Implementations could choose the more efficient Headers object representation even for a header list, as long as they also support an associated data structure for Set-Cookie headers.

Anyway, glad to hear if we can move on one day. @mcollina

Thx & B/R
Fred